Vibratory apparatus

ABSTRACT

A container is supported by a plurality of spring beams for oscillatory movement on an effective pivot axis offset laterally from a vertical center plane of the container, and a plurality of generally vertical coil springs cooperate with the spring beams to provide the container and the load therein with a resonant frequency of oscillation corresponding substantially to a predetermined excitation frequency. The coil springs are offset laterally from the vertical center plane of the container in spaced relation to the spring beams and are adjustable to provide for substantially maintaining the resonant frequency of oscillation with changes in the load. A cover member is positioned for exerting pressure on the load within the container and in one form is flexible with attached weights and in another form is substantially rigid and hinged to the container.

States Patet lsaacsnn [54] VIBRATORY APPARATUS [72] Inventor: Maxllsaacson, Dayton, Ohio [73] Assignee: Vibrodyne, llnc., Dayton, Ohio[22] Filed: Aug. 15, 1969 [2i] Appl.No.: 850,496

Primary ExaminerRobert W. Jenkins Attorney-Jacox & Meckstroth [57]ABSTRACT A container is supported by a plurality of spring beams foroscillatory movement on an effective pivot axis offset laterally from avertical center plane of the container, and a plurality of generallyvertical coil springs cooperate with the spring beams to provide thecontainer and the load therein with a resonant frequency of oscillationcorresponding substantially to a predetermined excitation frequency. Thecoil springs are offset laterally from the vertical center plane of thecontainer in spaced relation to the spring beams and are adjustable toprovide for substantially maintaining the resonant frequency ofoscillation with changes in the load. A cover member is positioned forexerting pressure on the load within the container and in one form isflexible with attached weights and in another form is substantiallyrigid and hinged to the container.

17 Claims, 6 Drawing Figures PATENTED JAMES m2 FIG-4 25 326 M/ VE/V TORMAX ISAACSON I My 4 TTORNE :5

VIBRA'IORY APPARATUS BACKGROUND OF THE INVENTION The invention relatesto a vibratory machine or apparatus as disclosed in lsaacson et al. US.Pat. No. 3,173,664, wherein a container is cantileveredly supported byspring beams for oscillatory movement on an axis offset laterally from avertical plane extending through the center of the container. In suchapparatus, it has been found desirable for some applications to increasethe weight of the work load of media within the eontainer withoutmaterially increasing the stress on the spring beams and withoutsignificantly changing the desired resonant frequency of oscillation ofthe container and the load, thereby maintaining the most effectiveoperation of the apparatus and the most efficient use of the power meansemployed for oscillating the container. It has also been found desirablefor some applications of the apparatus to obtain a more effective andintense rubbing action between the media and the parts placed within themedia so that the time required for surface finishing the parts issignificantly reduced.

SUMMARY OF THE INVENTION The present invention is directed to animprovedvibratory apparatus of the type including an oscillatory containeradapted to receive a work load of media and parts which are to besurface finished. The apparatus provides for supporting the container sothat a substantially predetermined resonant frequency of oscillation ofthe container and the load can be substantially maintained with changesin the weight of the load. The apparatus further provides for using amaximum load of media within the container without overflowing and forexerting pressure on the media to obtain a more intense and effectiverubbing action between the media and the parts placed within the mediafor surface finishing.

In accordance with one embodiment, the container is supported by aplurality of spring beams for oscillatory movement on an effective pivotaxis offset laterally from a vertical plane extending through the centerof the container. The container is also supported by a plurality of coilsprings which are offset laterally from the center plane of thecontainer in a direction opposite to the effective pivot axis. The coilsprings are effective to release part of the stress on the spring beamsand are adjustable individually so that they can be used to counteract achange of the load within the container as well as for counteractingvarying mass distribution of the container and for minimizing distortionof the container when vibrated under a loaded condition, therebysubstantially maintaining the predetermined resonant frequency ofoscillation of the container and load. The dynamic response of the coilspring or springs is selected conjunctively or in aiding relation withthe I spring beams to maintain the predetermined natural frequency ofthe system regardless of changes of load in the container.

Pressure is applied to the media by a flexible cover member having oneedge portion attached to the container and carrying a plurality ofweights. In accordance with another embodiment of the invention, thepressure on the media is applied by a substantially rigid cover memberhaving one edge hinged to the corresponding upper edge of the container.The cover members also provide for using a maximum load of media withinthe container by preventing the overflow of media as it orbits inresponse to oscillation of the container.

BRIEF DESCRIPTION OF THE DRAWING 34 of no. 2;

FIG. 4 is a fragmentary section taken generally on the line 4-4 ofFlG.2;

FIG. 5 is a fragmentary section similar to FIG. 3 and showing a modifiedform of the invention; and

FIG. 6 is a fragmentary section similar to FIG. 1 and showing anothermodification of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The vibratory apparatus shownin FIG. I includes a base frame 15 having parallel spaced vertical endwalls 16 rigidly connected by a cross plate 17, a channel member 18 anda bar 19. The frame 15 is mounted on resilient shock-absorbing feet 21located at the comers of the frame. A troughlike tub or container 25 ispositioned between the end walls I6 of the frame 15 and includesparallel spaced vertical end walls 26 rigidly connected by anintermediate wall having a U-shaped cross-sectional configuration. Thecontainer has an outwardly projecting peripheral flange 29, and thewalls 26 and 28 and flange 29 are covered with a plastic lining 30having parallel spaced ribs 31 defining a corrugated inner surface. Thelined container walls 26 and 28 define a chamber 35 having a rectangularhorizontal configuration and a U-shaped vertical configuration andadapted to receive a work load, for example, a media M of ceramic chipsor other abrasive materials and a suspended batch of parts P which areto be surface finished such as by a deburring, polishing or descalingoperation. The container 25 is positioned so that a longitudinal plane37 extending through the center of the chamber 35 is slightly inclinedfrom the vertical.

The container 25 is supported on one side of the center plane 37 by apair of I-shaped end spring beams 40 which connect the end walls 26 ofthe container to the end walls 16 of the frame 15. In addition, thecorresponding side of the intermediate wall 28 of the container 25 isconnected to the frame bar 19 by a plurality of intermediate springbeams 42 which are aligned with the end spring beams 40. The upper endportion of each spring beam 42 is secured by screws to a rail 44attached to the side of the intermediate wall 28, and the lower endportion of each spring beam 42 is clamped to the frame bar 19 by a plate43.

On the opposite side of the center plane 37, the container 25 issupported by a plurality of longitudinally spaced coil compressionsprings 45 which extend between the frame channel 18 and alongitudinally extending angle bracket 47 secured to the adjacent sideof the intermediate wall 28 of the container. The lower end of each coilspring 45 seats on a fitting 48 mounted on the upper end of a screw 49which can be adjusted to vary the upward force exerted by the spring onthe container 25.

The spring beams 40 and 42 establish an effective pivot axis 50 for thecontainer 25 and cooperate with the coil springs 45 to provide'thecontainer 25 with a predetermined resonant frequency of oscillation.This resonant. frequency is in the neighborhood of and generally above3,600 cycles per second when the apparatus is to be operated from a60-cycle power supply. After the load is placed within the container 25,the coil springs 45 are adjusted so that the resonant frequency of thesystem including the container, load, spring beams and coil springs, issubstantially 3,600 cycles per second.

The container 25 is oscillated by power-operated means including a pairof electromagnets 55 arranged in opposing relation on opposite sides ofa barlike armature 56 having ends rigidly connected to parallel spacedplates 58 secured to the intermediate wall 28 of the container 25. Eachmagnet 55 is mounted on a bracket 60 which is slidably supported by thecross plate I7 and is laterally adjustable by a set of screws 62. Eachmagnet 55 is adjusted before the container is loaded to form apredetermined uniform gap 61 between the armature 56 and each of theelectromagnets 55 according to thedesired amplitude of oscillation. Thearmature 56 is aligned with the spring beams 40 and 42 so that the gap61 between the armature and each magnet remains substantially uniformduring oscillation of the container 25 when the electromagnets 55 aresupplied with variable voltage 60-cycle AC power as men tioned above.When the load is placed within the container 25, the armature 56 movescloser to the magnet 55 on the left (FIG. 1). The adjustment of the coilsprings 45, as mentioned above, is effective to return the armature to aposition centered between the magnets.

As shown in FIGS. 1-4, a blanketlike cover member 65 extends over thechamber 35 and includes a sheet 66 of flexible resilient material suchas rubber which is adapted to rest upon the upper surface of the media Mwithin the container. The flexible sheet 66 is rectangular (FIG. 2)conforming to the shape of the chamber 35 and has a forward portionwhich is secured by a series of bolts 67 to a channellike clampingbracket 68. A set of longitudinally spaced screws 69 clamp the bracket68 to the outwardly projecting flange 29 of the container 25 and areeach secured by a set of lock nuts 71. The cover member 65 also includesa plurality of elongated weight members or bars 74 which are arranged inparallel spaced relation and as secured to the flexible sheet 66 by aseries of bolts 76 (FIG. 4).

In operation, when the container 25 loaded with media M and parts P, isoscillated about the pivot axis 50 in response to energizing of theelectromagnets 55, the media and suspended parts orbit in the directionof the arrows 78 (FIG. 1). As a result of the weight of the cover member65, pressure is exerted on the media M by the cover member 65 and thispressure is transferred to the surfaces of the parts P producing a moreintense and effective rubbing action between the media and the parts.The cover member 65 also serves to retain the media and parts within thechamber 35 and thereby prevents overflowing especially when the chamber35 is substantially full of media.

Referring to FIGS. 5 and 6, another form of cover member 80 includes asubstantially rigid rectangular sheet 82 of metal such as steel. Thesheet 82 is slightly curved (FIG. 6) and has sufficient thickness andweight to provide a substantial pressure on the media M in the samemanner as the weighted cover member 65. The forward longitudinal edgeportion of the sheet 82 is connected by a hinge 84 to the channel 68which is releasably clamped to the outer flange 29 of the container 25.A handle 85 is secured to the opposite edge portion of the sheet 82 andprovides for pivoting the cover member to an upright position (notshown) for loading parts or media into the container chamber. In aconventional manner, the media and parts are removed from the chamberthrough an opening 86 (FIG. 1) within one of the end walls 26 of thecontainer.

Referring to FIG. 6, a modified support of the container 25 includes apair of end spring beams 40 which are located in laterally offsetrelation to the center plane 37 of the container 25' in a manner asshown in the above patent. The spring beams 40' define an effectivepivot axis 50' for oscillatory movement of the container. In addition tothe spring beams 40', the container 25 is supported by a plurality oflongitudinally spaced adjustable coil springs 90 which extend between anangle bracket 92 secured to one side of the container wall 28 and achannellike crossmember 94 of the frame The coil springs 90 are offsetlaterally from the center plane 37' in the same direction as the springbeams 40 but are spaced at a further distance from the center plane 37.On the opposite side of the center plane 37, the container 25' issupported by a plurality of longitudinally spaced adjustable coilsprings 45' in a manner similar to the support of the container 25described above. The coil springs 45 cooperate with the coil springs 90and the spring beams 50 to support the container 25 and the load thereinfor oscillation at a resonant frequency corresponding substantially tothe predetermined frequency ofexcitation by the electromagnets 55.

From the drawing and the above description, it is apparent thatvibratory apparatus constructed in accordance with the present inventionprovides desirable features and advantages. For example, the auxiliarycoil springs 45 cooperate with the spring beams 40 and 42 to support thecontainer 25 for oscillatory movement on the effective pivot axis 50 andprevent overstressing the spring beams 40 and 42 when the container 5justed so that they exert an increased upward force on the container 25thereby counteracting the dampening effect of the increased load andretaining the container and the load to the predetermined resonantfrequency. As a result, the optimum vibratory energy is obtained fromthe electromagnets 55 which produce an excitation frequencycorresponding substantially to resonant frequency of the container andload.

Moreover, the adjustment of the coil springs 45 with an increased loadprovides for maintaining equal gaps 61 between the armature 56 and theelectromagnets 55. The same advantages are provided by the embodimentshown in FIG. 6. That is, the coil springs 45 and 90 cooperate with thespring beams 40 to support the container 25 and load for oscillation onthe effective pivot axis 50' at substantially the predetermined resonantfrequency without overstressing the spring beams 40'. When the load inthe container 25' is changed, the coil springs 45' and 90 are adjustedto maintain substantially the resonant frequency.

Another important feature of the invention is provided by the covermember 65 or 80. As mentioned above, each cover member is effectivetoexert a pressure on the media within the oscillatory container so thata more efficient and effective rubbing action is produced between themedia and the surfaces of the parts placed within the media. As aresult, the time required for surface finishing the parts issignificantly reduced. The cover members 65 and also provide forutilizing a maximum load within the container by preventing overflow ofthe media from the container.

While the forms of apparatus herein described constitute preferredembodiments of the invention, it is to be understood that the inventionis not limited to these precise fonns of apparatus, and that changes maybe made therein without departing from the scope and spirit of theinvention. For example, air spring members might be used in place of thecoil springs 45, 45 or 90.

What is claimed is:

l. Vibratory apparatus comprising a frame, a container defining achamber adapted to receive a load to be vibrated, means mounted on saidframe and supporting said container for oscillatory movement on apredetermined effective axis offset laterally in relation to a generallyvertical plane extending through the center of said container, saidsupporting means including spring means being effective to provide saidcontainer and the load therein with a resonant frequency correspondinggenerally to a predetermined frequency, poweroperated means foroscillating said container at substantially said predetermined frequencyto cause orbital movement of the load within said chamber, cover meansfor said container and extending over at least a portion of saidchamber, and means positioning said cover means for engaging the loadwithin said chamber to apply pressure on the load as it is beingorbited.

2. Vibratory apparatus as defined in claim 1 wherein said cover meanscomprise a flexible cover member, and means for connecting a portion ofsaid cover member to said container.

3. Vibratory apparatus as defined in claim 2 including weight meanssecured to said cover member to increase the effective weight of saidcover member and the corresponding pressure on the load within saidchamber.

4. Vibratory apparatus as defined in claim 1 wherein said cover meanscomprise a substantially rigid cover member, and hinge means connectingsaid cover member to said container.

5. Vibratory apparatus as defined in claim 1 wherein said container isgenerally U-shaped in vertical cross section, said means for positioningsaid cover means comprise a connection between said cover means and saidcontainer, and said connection being laterally offset from said plane ina direction opposite to that of said effective pivot axis.

6. Vibratory apparatus as defined in claim 1 wherein said spring meansinclude at least one spring beam connecting said container to said frameand defining said effective pivotaxis, and said spring means furtherinclude at least one coil spring laterally offset from said plane in adirection opposite to that of said effective pivot axis.

'7. Vibratory apparatus as defined in claim 6 including means foradjusting the force exerted by said coil spring on said container tocompensate for a change in the load within said chamber for maintainingsubstantially said resonant frequency of oscillation of said containerand the load therein.

8. Vibratory apparatus as defined in claim 6 wherein said spring meansfurther include at least one coil spring offset laterally from saidplane in the same direction as said pivot axis and being located at agreater distance from said plane than said pivot axis for cooperatingwith said coil spring on the opposite side of said plane to reduce theload supported by said spring beam.

9. Vibratory apparatus comprising a frame, a container defining achamber adapted to receive a load to be vibrated, at least one springbeam mounted on said frame and supporting said container for oscillatorymovement on an effective axis offset laterally in relation to agenerally vertical plane extending through the center of said container,at least one spring member connecting said frame to said container andspaced from said effective axis generally parallel with said plane toproduce a restraint on said container in a direction substantiallyopposite to gravity, said spring beam and said spring member cooperatingto support said container and the load therein for oscillation abovesaid axis at a resonant frequency corresponding substantially to apredetermined frequency, and poweroperated means for oscillating saidcontainer at substantially said predetermined frequency to cause orbitalmovement of the load within said chamber.

10. Vibratory apparatus as defined in claim 9 including means foradjusting the force exerted on said container by said spring memberaccording to the load within said chamber for substantially maintainingsaid resonant frequency of oscillation when the load within saidcontainer is changed.

11. Vibratory apparatus as defined in claim 9 including a plurality ofsubstantially aligned said spring beams and a plurality of substantiallyaligned spring members arranged in substantially parallel spacedrelation.

12. Vibratory apparatus as defined in claim 1] and further including aplurality of generally aligned spring members connecting said frame tosaid container and spaced laterally from said plane in the samedirection as said effective pivot axis and at a greater distance fromsaid plane than said pivot axis.

13. Vibratory apparatus as defined in claim 9 including cover means forsaid container and extending over at least a portion of said chamber,and means positioning said cover means for engaging the load within saidchamber to apply pressure on the load as it is being orbited.

l4. Vibratory apparatus as defined in claim 9 wherein said spring membercomprises a coil spring.

15. Vibratory apparatus comprising a frame, a container having aU-shaped cross-sectional configuration and defining a chamber adapted toreceive a load to be vibrated, a plurality of generally verticallyextending spring beams mounted on said frame and supporting saidcontainer for oscillatory movement on an effective pivot axis offsetlaterally in relation to a generally vertical plane extending throughthe center of said container, a plurality of generally verticallyextending coil springs connecting said frame to said container andspaced from said plane in a direction opposite to that of said effectivepivot axis, said spring beams and said coil springs supporting saidcontainer and the load therein for oscillation above said pivot axis ata resonant frequency corresponding generally to a predeterminedfrequency, a pair of electromagnets disposed in opposed spaced relation,an armature member connected to said container and extending betweensaid electromagnets and defining substantially uniform and equal gapsbetween said arrnature member and said electr-ornagnets saidelectromagnets being effective to oscillate said container atsubstantially said predetermined frequency to cause orbital movement ofthe load within said chamber, and means for adjusting the force exertedon said container by said coil spring for substantially maintaining saidgaps between said armature and said electromagnets and for substantiallymaintaining said resonant frequency when the load within said containeris changed.

16. Vibratory apparatus as defined in claim 15 including cover means forsaid container and extending over at least a portion of said chamber,and means positioning said cover member for engaging the load withinsaid chamber to apply pressure on the load as it is being orbited.

17. In vibratory apparatus including a frame, a container defining achamber adapted to receive a load to be vibrated, a plurality of springbeams mounted on said frame and supporting said container foroscillatory movement on an effective axis offset laterally in relationto a generally vertical plane extending through the center of saidcontainer, said spring beams supporting said container and the loadtherein for oscillation at a resonant frequency correspondingsubstantially to a predetermined frequency, and means for oscillatingsaid container at substantially said predetermined frequency to causeorbital movement of the load within said chamber, the improvementcomprising auxiliary spring means connecting said frame to saidcontainer in spaced relation to said effective axis, and means foradjusting the force exerted by said spring means on said container forsubstantially maintaining said resonant frequency of oscillation whenthe load within said container is changed.

1. Vibratory apparatus comprising a frame, a container defining achamber adapted to receive a load to be vibrated, means mounted on saidframe and supporting said container for oscillatory movement on apredetermined effective axis offset laterally in relation to a generallyvertical plane extending through the center of said container, saidsupporting means including spring means being effective to provide saidcontainer and the load therein with a resonant frequency correspondinggenerally to a predetermined frequency, power-operated means foroscillating said container at substantially said predetermined frequencyto cause orbital movement of the load within said chamber, cover meansfor said container and extending over at least a portion of saidchamber, and means positioning said cover means for engaging the loadwithin said chamber to apply pressure on the load as it is beingorbited.
 2. Vibratory apparatus as defined in claim 1 wherein said covermeans comprise a flexible cover member, and means for connecting aportion of said cover member to said container.
 3. Vibratory apparatusas defined in claim 2 including weight means secured to said covermember to increase the effective weight of said cover member and thecorresponding pressure on the load within said chamber.
 4. Vibratoryapparatus as defined in claim 1 wherein said cover means comprise asubstantially rigid cover member, and hinge means connecting said covermember to said container.
 5. Vibratory apparatus as defined in claim 1wherein said container is generally U-shaped in vertical cross section,said means for positioning said cover means comprise a connectionbetween said cover means and said container, and said connection beinglaterally offset from said plane in a direction opposite to that of saideffective pivot axis.
 6. Vibratory apparatus as defined in claim 1wherein said spring means include at least one spring beam connectingsaid container to said frame and defining said effective pivot axis, andsaid spring means further include at least one coil spring laterallyoffset from said plane in a direction opposite to that of said effectivepivot axis.
 7. Vibratory apparatus as defined in claim 6 including meansfor adjusting the force exerted by said coil spring on said container tocompensate for a change in the load within said chamber for maintainingsubstantially said resonant frequency of oscillation of said containerand the load therein.
 8. Vibratory apparatus as defined in claim 6wherein said spring means further include at least one coil springoffset laterally from said plane in the same direction as said pivotaxis and being located at a greater distance from said plane than saidpivot axis for cooperating with said coil spring on the opposite side ofsaid plane to reduce the load supported by said spring beam. 9.Vibratory apparatus comprising a frame, a container defining a chamberadapted to receive a load to be vibrated, at least one spring beammounted on said frame and supporting said container for oscillatorymovement on an effective axis offset laterally in relation to agenerally vertical plane extending through the center of said container,at least one spring member connecting said frame to said container andspaced from said effective axis generally parallel with said plane toproduce a restraint on said container in a direction substantiallyopposite to gravity, said spring beam and said spring member cooperatingto support said container and the load therein for oscillation abovesaid axis at a resonant frequency corresponding substantially to apredetermined frequency, and power operated means for oscillating saidcontainer at substantially said predetermined frequency to cause orbitalmovement of the load within said chamber.
 10. Vibratory apparatus asdefined in claim 9 including means for adjusting the force exerted oNsaid container by said spring member according to the load within saidchamber for substantially maintaining said resonant frequency ofoscillation when the load within said container is changed. 11.Vibratory apparatus as defined in claim 9 including a plurality ofsubstantially aligned said spring beams and a plurality of substantiallyaligned spring members arranged in substantially parallel spacedrelation.
 12. Vibratory apparatus as defined in claim 11 and furtherincluding a plurality of generally aligned spring members connectingsaid frame to said container and spaced laterally from said plane in thesame direction as said effective pivot axis and at a greater distancefrom said plane than said pivot axis.
 13. Vibratory apparatus as definedin claim 9 including cover means for said container and extending overat least a portion of said chamber, and means positioning said covermeans for engaging the load within said chamber to apply pressure on theload as it is being orbited.
 14. Vibratory apparatus as defined in claim9 wherein said spring member comprises a coil spring.
 15. Vibratoryapparatus comprising a frame, a container having a U-shapedcross-sectional configuration and defining a chamber adapted to receivea load to be vibrated, a plurality of generally vertically extendingspring beams mounted on said frame and supporting said container foroscillatory movement on an effective pivot axis offset laterally inrelation to a generally vertical plane extending through the center ofsaid container, a plurality of generally vertically extending coilsprings connecting said frame to said container and spaced from saidplane in a direction opposite to that of said effective pivot axis, saidspring beams and said coil springs supporting said container and theload therein for oscillation above said pivot axis at a resonantfrequency corresponding generally to a predetermined frequency, a pairof electromagnets disposed in opposed spaced relation, an armaturemember connected to said container and extending between saidelectromagnets and defining substantially uniform and equal gaps betweensaid armature member and said electromagnets, said electromagnets beingeffective to oscillate said container at substantially saidpredetermined frequency to cause orbital movement of the load withinsaid chamber, and means for adjusting the force exerted on saidcontainer by said coil spring for substantially maintaining said gapsbetween said armature and said electromagnets and for substantiallymaintaining said resonant frequency when the load within said containeris changed.
 16. Vibratory apparatus as defined in claim 15 includingcover means for said container and extending over at least a portion ofsaid chamber, and means positioning said cover member for engaging theload within said chamber to apply pressure on the load as it is beingorbited.
 17. In vibratory apparatus including a frame, a containerdefining a chamber adapted to receive a load to be vibrated, a pluralityof spring beams mounted on said frame and supporting said container foroscillatory movement on an effective axis offset laterally in relationto a generally vertical plane extending through the center of saidcontainer, said spring beams supporting said container and the loadtherein for oscillation at a resonant frequency correspondingsubstantially to a predetermined frequency, and means for oscillatingsaid container at substantially said predetermined frequency to causeorbital movement of the load within said chamber, the improvementcomprising auxiliary spring means connecting said frame to saidcontainer in spaced relation to said effective axis, and means foradjusting the force exerted by said spring means on said container forsubstantially maintaining said resonant frequency of oscillation whenthe load within said container is changed.